In order to predict how crowded public transportation is for commuters, Google Maps asked users if they traveled during the peak hours of 6am to10am, and then inquired about seat availability and standing room in buses or trains, attempting to identify which lines had the highest number of crowdedness reports. They then use this data to form a new prediction capability designed to tell transit riders how crowded their bus or train will be. Through the combination of bus route details and data collected from users, traveling has been made easier.
Read more about it here.